Means for regulating the supply of liquid to vapor-generators.



1'. WILKINSON.

MEANS FOR REGULATING THE SUPPLY OF LIQUID T0 VAPOR GENERATORS.

APPLICATION FILED FEB. 6. 19l2.

1 ,154,467. Patented Sept. 21, 1915.

2 SHEETS-SHEET Witnesses: Inventor:

WfM James Wilkinson,

y MW Hisflttorne g.

J. WILKINSON.

MEANS FOR REGULATING THE SUPPLY OF LIQUID T0 VAPOR GENERATORS.

APPLICATION FILED FEB. 6 1912.

Patented Sept. 21, 1915.

2 SHEETSSHEE| 2.

Witnesses: Inventor:

James Wilkinson, 5 MM MfW His flttorne g.

, UNITED STATES PATENT OFFICE.

JAMES WILKINSON, OF BOSTON, MASSACHUSETTS, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION 01 NEW YORK.

MEANS FOR BEGULATING THE SUPPLY OF LIQUID TO VAIfOB-GENEBATORS.

Specification of Letters Patent.

Patented'Sept. 21, 1915.

continuation of application Serial No. 660,529, filed January 5, 1912. This application filed February 8,

1912. Serial No. 075,850.

To all whom it ma concern:

Be it known that I, JAMES WILKINSON, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented certain new and useful Improvements in Means for Regulating the Supply of Liquid to Vapor-Generators, (the present application being a continuation of my pending application Serial No. 669,529, filed January 5, 1912,) of which the following is a specification.

The present invention relates to automatic means for regulating the supply of liquid, such as water, to vapor generators or boilers and has for its object to improve their construction and operation.

Automatic regulators depending upon the level of water in boilers have heretofore been constructed. These I have found to be defective in certain material aspects, especially where a number of boilers are arran ed in a battery and supply steam in para lel to a common header or main. In service it has been found that boilers so arranged steam very irregularly at times due chiefly to what may be termed interference between boilers. To illustrate the nature and effect of boiler interference attention is called to the fact that the rate of steaming of a boiler is extremely sensitive to variations of either the temperature or the ressure within the boiler and that the efliclency varies with this rate.

When the temperature and pressure are uniform throughout all the members of a battery, each boiler will then be generating its share of the steam, and the battery as a whole will be generating steam with an efficiency in accordance with the load, or with What may be termed unit efficiency. That is with the same efficiency with which an imaginary single boiler would perform the work. lVhen interference is permitted to occur this condition no longer prevails. The effect of interference is to cause boilers to assume unequal shares of the total load. Assuming that the highest point of efficiency is 72%, at 1% rated 'load it is 70% and at 1 load 62%. Then if three divisions of a battery are steaming according to these various ratings the battery efliciency will be only 94% of unit eflicieney, or the efliciency which would have been obtained if the load had been divided equally.

The reduction in output of the one which I will term the lagging boiler is greater, for a given cause, than would be the case if the same boiler was, for instance, the sole unit supplyin an inde endent service. The decrease'in e iency o the lagging boiler is also greater for a given reduction in rate of steaming than in an independent boiler. These excess losses are believed to be caused by the retardation of the circulation of water in a boiler whenever interference acts to abnormally reduce its rate of steaming which is in turn accompanied by less active circulation of the water which, theoretically at least, will cause the heat transfer to be less eflicient.

Interference is produced by anything that will cause a slight reduction of ressure in one or a portion of the boilers o a battery, such for instance, as suddenly increasing the rate of water input. Pressure reduction is accompanied by a reduction in the rate of steaming of the affected boiler. This has the effect of lowering the general steam pressure in the steam piping which in turn causes the other boilers to steam at a greater rate in order to make u the deficiency.

To obtain the most e cient result from a battery of boilers it is therefore essential that interference be avoided. This is accomplished by so governing the several boilers that they will at all times assume their proper shares of the load. The fires must be maintained continuously uniform by automatic regulation of the draft in accord ance with the load. The feed water must be supplied continuously and at the same instantaneous rate of flow in pounds per hour as the steam output. The latter necessity requires that the feed water be governed by automatic means, and that this regulative action be primarily influenced by the rate of flow of the steam delivered by the boiler.

I overcome the objectionable features above referred to by providing a regulating mechanism for the boiler feed pump which takes into account or is sensitive to changes in the rate of flow of steam issuing from each boiler, as distinguished from changes in water levels therein. This is a very important feature because the instant the rate of flow changes the supply of water should be correspondingly changed. In such a case the regulating mechanism anticipates, so to speak, the change in water level because the said level does not instantly change whereas the flow does. By thus anticipating changing conditions the supply of water can be rendered proportional to the load and the best steaming efl'ects obtained. The regulating mechanism is further so arranged that it takes into account changes in water level in the boiler thereby preventing all danger from under or over feeding. The regulating mechanism which is thus made sensitive to the two essential features of boiler regulation is arranged to automatically control the pump that supplies water to the boiler or to directly control the admission of water.

In carrying out my invention an agent, such as a Pitot or a Venturi tube or other means, is located in the main conveying steam from the boiler. Such a device will create a pressure diflerence that varies with changes in the rate of flow of the steam leaving the boiler. This pressure difference is communicated to a member of the regulating mechanism whose position is changed by changes in said pressure difference. Such member is arranged to tilt or move in one direction or the other. This is brought about by pivotally supporting the member and providing it with a chamber containing mercury or some other heavy fluid. The chamber is subjected to the pressure difference caused by the Pitot tube or other means or device and as the mercury or other fluid is deflected from one side of the pivot or axis of the member to the other, the latter will be correspondingly tilted or moved. The amount of movement, tilt or deflection is directly dependent upon said pressure diiference.

To the tiltin or movable member is attached means or actuating either directly or indirectly the controlling valve of the pump for startin and stopping it, the said valve and pump eing of any suitable form or construction, or a valve merely controlling the admission of Water may be provided and actuated directly or indirectly by the member.

In order to take into account the changes in water level the tiltin or movable member is provided with a oat whose position is determined b the level of the water in the boiler. ThlS float modifies the action of the said member to the extent that it prevents the level of the water from rising too high or falling too low. This float also acts as a restoring means to restore the member to its initial position whenever the pump has supplied the boiler with the nacessary amount of water. In this manner it acts to prevent an excess of water entering the boiler. As a result of the conjoint action of the agent, member and float, the pump or other means will supply water to the boiler continuously and in exact accordance with the steam output. The said member and the float may be located within the boiler proper or they may be located in a separate casing communicating with the boiler and to which the water and steam have access. In addition to the above, the said member may be provided with an indicating device external to the boiler or casing by means of which the attendant can readily determine the rate at which steam is being discharged or water admitted at a given instant.

As one embodiment of my invention I have shown a steam driven pump with its controlling valve actuated or controlled by the movements of said member but it is to be understood that the pump may be driven by any suitable type of motor in which case the controller or regulator therefor will be modified to suit its character.

In the broader aspects of my invention it is immaterial whether the said member directly controls the amount of fluid admitted to the boiler or generator or whether it controls the motor that drives the pump.

In the accompanying drawings which are illustrative of my invention, Figure 1 is a. view partly in section and partly in elevation of my improved boiler feeding mechanism; Fig. 2 is a similar view of a modified form of the invention wherein the member that is sensitive to changes in the rate of flow of the vapor discharged by the boiler is located in a water column; Fig. 3 is a further modification wherein the admission of feed water to the boiler is directly controlled as distinguished from controlling the admission of steam to the motor that drives the pump; Fig. 4 is a detail view of a slightly modified form of mercury containing member, and Fig. 5 is a detail view of a means for creating a pressure difl'erence.

1 indicates a boiler of any suitable type or construction and 2 the conduit leading therefrom and conveying steam to a header or other receiving device. The boiler may act alone to supply steam to the consumption devices or it may be one of a battery all of which supply steam in parallel to a header or other receiving means.

3 indicates a feed pump of any suitable construction for supplying water to the boiler through the conduit 4. As shown this pump is of the centrifugal type. The pump is driven by a steam turbine or other motor 5 which is supplied with steam from the boiler by the pipe 6. The admission of steam to this pi e is controlled by the balanced piston va ve 7, located in this case within the steam s ace of the boiler.

Situated in the ischarge conduit 2 is an agent 8 of any suitable construction for creating a ressure difference that is responsive to c anges in the rate of flow of steam passing through said conduit. It comprises 1n the present illustration a Pitot tube wherein 9 is the leading nozzle orifice and 10 the trailing nozzle orifice. Located within the boiler is a member or lever 11 that is supported on the pivot 12, the latter being carried by a bracket 13 affixed to one wall of the boiler. The center of the pivot is substantially in line with the mean water level. The member 11 is provided with a chamber 14 that surrounds the pivot 12 and contains a body of mercury 15. As this mercury is deflected from one side of the pivot to the other it causes the member to tilt, oscillate or move about its pivot. Th pressure difference due to the agent 8 is conveyed to the opposite ends of the mercury containing chamber by the small pipes 16 and 17. These pipes are suitably packed at 18 where they pass through the boiler wall and are provided with flexible ends at the points where they communicate with the chamber so as to ofi'er as small opposition as possible to movements of the member. This is accomplished by curving the ends of the pipe in an arc as shown. As the pressure difference due to the action of the agent changes the member is moved by an amount dependent upon said pressure difference in a clock-wise or anti-clock-wise direction, as the case may be, and the movement thereof is communicated to the pump controlling valve 7 by the rod 19, which is linked to the member. As shown, the valve 7 is open and the motor 5 is driving the pump 3 and the latter is supplying Water to the boiler.

The buoyancy of the float 20 is also utilized to adjust the parts to cause an amount of water to be admitted to the boiler that is the exact equivalent of the steam discharged through the conduit 2. The float 20 is acted upon by the level of the water in the boiler, and thus prevents the pump from delivering too much or too little water. The float is attached to the member by suitable means such for example as the arms 21. This float also acts to restore the member to its initial position. From the foregoing it will be seen that the pump valve or controller 7 is controlled by two means, one sensitive to changes in the rate of flow of the vapor discharged by the boiler. the other sensitive to changes in the level of water in the boiler. The apparatus is so proportioned that any given rate of steam flow from the boiler in pounds per hour will cause a shifting of the mercury that will weight or load the float so that it will be submer ed (at the normal-valve closed-water leve by an amount just suflicient to open the feed valve or its equivalent and permit an inflow of water from the pump or other source e uivalent in pounds per hour to the steam ow.

Referring to Fig. 2, the member 11 instead of being located directly in the boiler is located in a water column 22 of suitable construction that communicates with the interior of the boiler by pipes 23 and 24, shown in dotted lines. It is also provided with a gage glass 25 of usual construction by means of which the level of the water within the boiler can be ascertained, and also with try cocks 26. In this instance the valve controlling the admission of steam to the pump motor 5 is relayed. To this end the spindle 12 of the member 11 is provided with a gear 27 meshing with a rack 28. To the lower end of the rack is connected a floating lever 40, the latter being pivotally attached to a piston valve 29 that controls the admission of fluid under pressure to and from a cylinder 30. Located Within the cylinder is a piston 30 which operates the valve 31 in the admission pipe leading to the pump motor. The rod 41 is extended above the piston and is connected to the lever 40. The lever 40 and rod 41 form a follow-up device to prevent over travel of the motor piston, and also to permit of holding the valve 31 in intermediate positions. Such an arrangement is desirable because it permits of closely regulating the passage of steam to the motor driving the pump or the admission of water directly to the boiler.

In order to indicate the amount of steam flowing through the conduit 2 an indicating device 32 is provided comprising a sector that is mounted on the spindle 12 which is moved by the mercury containing member 11. This sector is suitably calibrated to indicate the number of pounds of steam and water flowing per unit of time. As the sector is moved a comparison between it and the water level as shown by the gage glass will indicate the flow of steam or input of water in pounds per hour.

In Fig. 3 is shown a further modification wherein the admission of water to the boiler is controlled directly as distinguished from controlling the speed of the motor for driving the pump. In this figure 33 indicates the pipe through which water flows from a pump or other water supplying means to the boiler. This is controlled by a balanced valve 34 which is moved by the mercury containing member 11, the latter having arms 35 and 36 which respectively engage the top and bottom of the valve. Such a valve is capable of assuming intermediate positions. In this figure the structure of the float IS the same as that shown in Fig. 2. That is to say, the float 20 is made of ollow metal and is connected by a web 37 with the member 11. Stops 38 are provided to limit the u per and lower limits of movement of t e float. Since the arrangement of the other parts is the same as that previously described, further description 1s unnecessary.

The operation of my improved mechanism is as follows :Assuming for example that the demand of steam increases accompanied by a drop in pressure, a greater amount of steam Wlll flow through the conduit 2. Since the agent 8 is located in the conduit and since an increase in rate of flow will cause an increased dpressure difference, due to the action of sai agent, the efiect of the increased discharge by the boiler will at once he felt by the mercury containing member 11. As a result of this, the mercury will be deflected from the right-hand side of a plane passing vertically through the axis 12 to the left-hand side, which will cause the member to be moved in an anti-clock-wise direction, and this before a change in the level of the water in the boiler could possibly take place, thereby anticipating as it were the re uirements on the boiler. The movement 0 the mercur containing member 11 in an anti-clockwise direction opens the valve 7 and causes the inotor 5 to start and drive the feed pump, or if the valve be open, to increase its opening thereby increasing the speed of the motor. If the demand for steam now decreases, the agent 8 will immediately decrease the pressure diflerence and the mercury will shift within the member 11 and the float will act to restore the member to its initial or neutral osition where the valve 7 is closed, partially or wholly depending upon conditions. In addition to restoring the mercury containing member 11 to its initial position, the float 20 also prevents the water in the boiler from assuming a too high or too lOW a level. In Fig. 2 the operation is the same except that the controlling valve for motor driving the pump is relayed. In Fig. 3 the operation is the same except that the valve 34 directly controls the admission of water instead of controlling the supply of steam or other source of power to the motor driving the feed pump.

In Fig. 4 is shown a slight modification of the mercury containing member that is adapted for use where the steam flow is low. This differs chiefly from the ones heretofore described in that as the mercur is deflected from the right to the left its e ective leverage is increased. That is to say in the former cases the mercury moved in a path concentric with the axis of the pivot 12, while in the present case a portion of the body of mercury is also moved radially from said axis. This effect is obtained by making the mercury chamber of involute form as shown at 39. The arrangement described is of special benefit for those cases where the pressure difierence created y an agent in the steam main such as 2, is small. As an example of a diflerent form of agent for creating a pressure difl'erence, I may tap the discharge main 2 at diflerent points, preferably rather widely separated, and connect the pipes 16 and 17 to said taps. In such a case I may dispense with the tubes 9 and 10 within the .main. With the pipes 16 and 17 thus arranged there will be obtained a drop in pressure which varies with changes in the rate of flow of the steam issuing from the boiler. By locatin one tap on one side of an elbow 42 as in 5 and the other beyond it, the pressure ifl'erence due to variations in the rate of flow will be greater for a 'ven change.

11 accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. In combination, a boiler, a source of liquid supply therefor, a conduit discharging vapor from the boiler, and means responsive to changes in the rate of flow of vapor through the conduit for progressively increasing the amount of liquid per unit of time delivered by said source to the boiler as said rate of flow increases and for progressively reducing the supply of liquid per unit of time as said rate of vapor flow decreases.

2. In c0mbinati0n,a vapor generator,means supplying liquid thereto, a conduit for discharging vapor from the generator, means movable in response to changes in the rate of flow of the vapor in the discharge conduit and after it leaves the generator for progressively varying the amount of liquid admitted to the generator from said supply means, and means responsive to changes in level of the liquid in the generator which acts in opposition to movable means.

3. In combination, a vapor generator, means supplying liquid thereto, a conduit for discharging vapor from the generator, means for creating a pressure difference, the value of which varies with changes in the rate of flow of vapor through the conduit, means responsive to said pressure difference for progressively increasing the amount of liquid admitted to the generator as said rate of flow of vapor increases, and for progressively decreasing the supply as said rate decreases, and a device acted u on by the body of liquid in the generator or modifying the action of said pressure responsive means.

4. .In combination, a boiler, a feed pump therefor, a conduit discharg ng vapor from the boiler, means for creating a pressure difference that varies with changes in the rate of flow of vapor increases, and for proresponsive to said pressure dlflerence for rogressively increasing the efiectlve deiivery of liquid by the pump to the boiler as said rate of flow increases and progress vely decreasing it as said rate of flow decreases, and a device responsive to changes in level of the liquid in the boiler for preventlng said pressure responsive means from admitting liquid after a predetermined level has been reached.

5. In combination, a boiler, a feed pump therefor, a conduit discharging vapor from the boiler, a movable member whose position progressively changes with changes in the rate of flow of vapor through the conduit, a controller for the pump arranged to pro ressively increase its output as sa1d rate of ow increases and to progresslvely decrease it as said rate of flow decreases, and a device for transmitting movements of the member to the controller.

6. In combination, a boiler, a feed pump, a driving motor for the pump,'a regulator for the motor, a conduit discharging vapor from the boiler, means which progressively changes its position in response to changes in the rate of flow of the fluid passing through the conduit, and a device for transmitting motion from the said means to the re ulator.

In combination, a vapor generator, means supplying liquid thereto, a conduit for discharging vapor from the generator, an agent acted upon by the vapor flowin in the conduit for creating a pressure di erence which varies with changes in the rate of flow of said vapor, and a member sensitive to said pressure difference for progressively controlling the action of the liquid supplying means.

In combination, a vapor generator, means supplying liquid thereto, a conduit for discharging vapor from the generator, an agent acted upon by the vapor flowing in the conduit for creating a pressure difference which varies with changes in the rate of flow of said vapor, a movable member whose position at all times is determined by' the pressure diflerence caused by said agent and by the level of liquid in the generator, and a controller for the means which is res onsive to movements of said member.

9. Ii; combination, a boiler, a feed pump therefor, a conduit for discharging .vapor from the boiler, an agent for creating a pressure difl'erence that is responsive to changes in the rate of flow of the vapor discharged by the boiler, a pivotally supported memher which is moved by an amount dependent upon said pressure difference, a float that is acted upon by the liquid in the boiler and exerts its force on the member, and a means controlling the efiective dehvery of the gimp which is controlled by the said mem- 10. In combination, a boiler, a feed pump therefor, a conduit for discharging vapor from the boiler, an agent for creating a pressure difference that is responsive to changes in the rate of flow of the vapor discharged by the boiler, a pivotally supported mem or having a fluid containing chamber which is subjected to the action of the agent, a float that is attached to and moves with the member, and a valve that is actuated by :ihe combined action of the member and the oat.

11. In combination, a boiler, a feed pump, a conduit discharging steam from the boiler, an agent actuated upon by the steam for creatlng a pressure difference that varies with the rate of flow, a tilting member that has a mercury containing chamber which is subjected to the action 0 the agent, flexible conduits conveying fluid under pressure from the agent to the chamber, a float attached to the member which moves in response to changes in water level in the boiler for modifying the action of the agent, and a valve actuated by the member for controlling the admission of water to the boiler.

12. In combination, a boiler, a feed pump therefor, a conduit discharging vapor from the boiler, an agent acted upon by the vapor in the conduit that creates a pressure difference responsive to changes in the rate of vapor flow, a member whose movements are determined by the action of the agent, a means controlling the admission of liquid to the boiler that is actuated by the member. and an indicator moved by the member to show the rate of flow of the vapor leaving the boiler.

13. In combination, a boiler, a feed pump therefor, a conduit discharging vapor from the boiler, an agent acted upon by the vapor in the conduit that creates a pressure differenoe responsive to changes in the rate of vapor flow, an oscillating member having a mercury containing chamber within which said mercury is deflected by the action of the a ent to move the member, a float-connecte to the member and movable in response to changes in water level in the boiler to modify the action of the agent and said member, and a valve means actuated by the member for controlling the admission of liquid from the pump to the boiler.

14. In combination, a boiler, a water column connected thereto, a conduit discharging steam from the boiler, an agent responsive to changes in the rate of flow of steam through the conduit, an oscillating member located in the column and containing a body of mercury which is deflected by a greater or lesser amount due to the agent to move said member, a feed pump, and means actuated by the member for controlling the admission of water from the pump to the boiler. 4

15. In combination, a boiler, means for supplying water thereto, a conduit discharging steam from the boiler, an agentacted upon by steam for-creating a pressure difference that is responsive tochanges in the rate of flow of the fluid passing through the conduit, a member that is pro essively moved by an amount determme by said pressure difl'erence, a means opposing certain movements of the member and tending to restore it to its initial position, and a means lating the supply of water to the boiler which is controlled by the movements of said member. I I

16. In an apparatus of the character described, the combination of a conduit through which a fluid flows, an agent located in said conduit which creates a pressure difference which bears a definite relation to the rate of flow of fluid through said conduit, a pivotally supported member having an involute chamber therein containing a heavy fluid, and pipes connecting said agent to the chamber for subjecting the chamber to the pressure difierence to cause said member to move about its pivot.

17. In an apparatus of the character described, the combination of a conduit through which a fluid flows, an agent located in said conduit which creates a pressure difference which bears a definite relation to the rate of flow of fluid through said conduit, apivotally supported member having a fluid containing chamber, said chamber extending on both sides of a vertical plane passing through the axis of the pivot,

said chamber being so shaped and arranged that as the fluid volume is deflected from its initial position a lportion of it gradually moves away from t e pivot of said member, and pipes connecting said agent to the chamher for subjecting the chamber to the pressure difference to cause said member to move about its pivot.

18. In a boiler feed regulating system, the combination with the boiler, of means res onsive to variations in the water level therein for varying the supply of feed water to the boiler, and means res onsive to the flow of steam out of the boi er tending to progressively increase the supply of feed water as said steam flow increases.

19. In a boiler feed regulating system, the combination with the boiler, of primary means responsive to variations in the water level in the boiler for regulating the supply decrease the supp y of said water as the flow of steam and decreases.

20. Thecombination with a steam boiler of means sensitive to changes in the rate of flow of steam from said boiler, a means senout of the boiler increases sitive to changes in water level in said boiler, and means controlled by both said means for re lating the admission of feed water to sai boiler.

21. The combination with a steam boiler,

of a feed water pipe therefor, a valve controlling said pipe, means controlled by changes in the water level insaid boiler for regu ating said valve, and means controlled by the rate of flow of steam from said boiler for also controlling said valve, said last named means being adapted to operate said valve independently of the level of the water in the boiler.

22. In combination, a vapor generator, a means for supplying liriuid thereto to be vaporlzed, a regulator or said means, a lever for actuatmg the regulator, a means sensitive to changes in the rate of flow of vapor from the generator for moving the lever, and a device sensitive to variations in the level of the liquid in the generator which also acts on the lever to move the regulator.

23. In combination, a vapor generator, means supplying liquidthereto, a regulator therefor, a discharge main for the generator, an agent located inthe main which creates a presspre that varies with changes in the rate of flow of vapor through the main, a means acted uplon by the pressure due to the action of t e agent, a lever moved by the means for controlling the action of the regulator, andameans res onsive to changes in the level of the liqui in the generator which also moves the lever.

24. In a boiled feed re ulator, the combination of valve means 5)! controlling the supply of feed water to the boiler, means responsive to variations in the water level in the boiler which operates on said valve means to regulate the feed water supply, and means responsive to chan in the rate of flow of vapor from said bOl or which also operates on said valve means to regulate the feed water supply.

In witness whereof, I have hereunto set my hand this 5th day of February, 1912.

JAMES WILKINSON.

Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

It is hereby certified that in Letters Patent No. 1,154,467, granted September 21,

1915, upon the application of James Wilkinson, of Boston, Massachusetts, for an improvement in Means for Regulating the Supply of Liquid to Vapor-Generators, errors appear in the printed specification requiring correction. as follows: Page 5,

line 7, claim 4, strike out the words and syllable increases, and for proand insert the words through the conduit, means; same page, line 87, claim 11, for the word actuated read acted; page 6, line 110, claim 24, for the word boiled read boiler; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 1st day of February, A. D., 1916.

[SEAL] J. T. NEWTON,

Acting Commissioner of Patents. Cl. 103-86 

